I have an iMac and a Mac Mini and I'm also getting ready to buy a MacBook Pro. My primary machine, the iMac, is where I do a lot of my work and where I keep a lot of my files. However, I want to be able to access these files from the other devices. I don't want to store them in the cloud as there is sensitive business info that I do not want there. I also don't want to turn on file sharing. I can transfer the folders when I need through a Flash Drive. What I want to know is when I copy the files and folders to the Mini or the MB is there a way to tell the system only to copy new files or ones that are more recent rather than overwriting every file? I don't want to constantly have to copy GBs worth of data to keep my systems current and this would also keep wear and tear down on my SSDs.